''' FILE NAME lab_app.py Version 9 1. WHAT IT DOES This version adds support for Plotly. 2. REQUIRES * Any Raspberry Pi 3. ORIGINAL WORK Raspberry Full Stack 2015, Peter Dalmaris 4. HARDWARE * Any Raspberry Pi * DHT11 or 22 * 10KOhm resistor * Breadboard * Wires 5. SOFTWARE Command line terminal Simple text editor Libraries: from flask import Flask, request, render_template, sqlite3 6. WARNING! None 7. CREATED 8. TYPICAL OUTPUT A simple web page served by this flask application in the user's browser. The page contains the current temperature and humidity. A second page that displays historical environment data from the SQLite3 database. The historical records can be selected by specifying a date range in the request URL. The user can now click on one of the date/time buttons to quickly select one of the available record ranges. The user can use Jquery widgets to select a date/time range. The user can explore historical data to Plotly for visualisation and processing. // 9. COMMENTS -- // 10. END ''' from flask import Flask, request, render_template import time import datetime import arrow import json import plotly import sqlite3 import sys import Adafruit_DHT import ConfigParser from plotly.graph_objs import * config = ConfigParser.ConfigParser() config.read("/home/pi/Documents/pi-temp/config.ini") #It is important to provide an #absolute path to the config #file, otherwise rc.local won't be #able to find it! port = config.getint('SERVER', 'PORT') sensor = config.get('SENSOR','TYPE') app = Flask(__name__) app.debug = True # Make this False if you are no longer debugging @app.route("/") def lab_temp(): humidity, temperature = Adafruit_DHT.read_retry(getattr(Adafruit_DHT,sensor), 17) temperature = temperature * 9/5.0 + 32 if humidity is not None and temperature is not None: return render_template("live.html",temp=temperature,hum=humidity) else: return render_template("no_sensor.html") @app.route("/history", methods=['GET']) #Add date limits in the URL #Arguments: from=2015-03-04&to=2015-03-05 def history(): temperatures, humidities, timezone, from_date_str, to_date_str, range_hours = get_records() # Create new record tables so that datetimes are adjusted back to the user browser's time zone. time_series_adjusted_temperatures = [] time_series_adjusted_humidities = [] time_series_temperature_values = [] time_series_humidity_values = [] for record in temperatures: local_timedate_series = arrow.get(record[0], "YYYY-MM-DD HH:mm").to(timezone) time_series_adjusted_temperatures.append(local_timedate_series.format('YYYY-MM-DD HH:mm')) time_series_temperature_values.append(round(record[2],2)) for record in humidities: local_timedate_series = arrow.get(record[0], "YYYY-MM-DD HH:mm").to(timezone) time_series_adjusted_humidities.append(local_timedate_series.format('YYYY-MM-DD HH:mm')) #Best to pass datetime in text #so that Plotly respects it time_series_humidity_values.append(round(record[2],2)) temp = Scatter( x=time_series_adjusted_temperatures, y=time_series_temperature_values, name='Temperature', mode='lines', line=Line(color='red') ) hum = Scatter( x=time_series_adjusted_humidities, y=time_series_humidity_values, name='Humidity', line=Line(color='aqua') ) data = Data([temp, hum]) layout = Layout( title="Temperature and Humidity", xaxis=XAxis( type='date', autorange=True ), yaxis=YAxis( title='Fahrenheit / Percent', type='linear', autorange=True ), ) fig = Figure(data=data, layout=layout) graphJSON = json.dumps(fig, cls=plotly.utils.PlotlyJSONEncoder) ## Duration of significant heat increases # Timestep from raw database values for temperature timestep_minutes = int(round((datetime.datetime.strptime(temperatures[1][0], "%Y-%m-%d %H:%M:%S")-datetime.datetime.strptime(temperatures[0][0], "%Y-%m-%d %H:%M:%S")).seconds/60)) if (timestep_minutes == 0): timestep_minutes = 1 # Calculate minutes for each streak streak_minutes = streak_lengths(time_series_temperature_values)*timestep_minutes streak_minutes = [x-1 for x in streak_minutes if x > 2] #Turn this into a duration, filter out < 2 # Send output to page return render_template("history.html", timezone = timezone, graphJSON = graphJSON, total_minutes = sum(streak_minutes), range_hours = range_hours, from_date = from_date_str, to_date = to_date_str, debug = streak_minutes, ) # Calculate streak lengths. Based on https://stackoverflow.com/a/33403822/2152245. def streak_lengths(x): # find the boundaries where numbers are not consecutive boundaries = [i for i in range(1, len(x)) if x[i] <= x[i-1]] # add the start and end boundaries boundaries = [0] + boundaries + [len(x)] # take the boundaries as pairwise slices slices = [boundaries[i:i + 2] for i in range(len(boundaries) - 1)] # extract all sequences with length greater than one temporary = [x[start:end] for start, end in slices if end - start > 1] # Remove tuples with all equal values screened = [x for x in temporary if not all(y==x[0] for y in x)] # Calculate length of each list out = [len(x) for x in screened] return out def get_records(): from_date_str = request.args.get('from',time.strftime("%Y-%m-%d 00:00")) #Get the from date value from the URL to_date_str = request.args.get('to',time.strftime("%Y-%m-%d %H:%M")) #Get the to date value from the URL timezone = request.args.get('timezone','Etc/UTC'); range_h_form = request.args.get('range_h',''); #This will return a string, if field range_h exists in the request range_h_int = "nan" #initialise this variable with not a number print "REQUEST:" print request.args try: range_h_int = int(range_h_form) except: print "range_h_form not a number" print "Received from browser: %s, %s, %s, %s" % (from_date_str, to_date_str, timezone, range_h_int) if not validate_date(from_date_str): # Validate date before sending it to the DB from_date_str = time.strftime("%Y-%m-%d 00:00") if not validate_date(to_date_str): to_date_str = time.strftime("%Y-%m-%d %H:%M") # Validate date before sending it to the DB print '2. From: %s, to: %s, timezone: %s' % (from_date_str,to_date_str,timezone) # Create datetime object so that we can convert to UTC from the browser's local time from_date_obj = datetime.datetime.strptime(from_date_str,'%Y-%m-%d %H:%M') to_date_obj = datetime.datetime.strptime(to_date_str,'%Y-%m-%d %H:%M') # If range_h is defined, we don't need the from and to times if isinstance(range_h_int,int): arrow_time_from = arrow.utcnow().replace(hours=-range_h_int) arrow_time_to = arrow.utcnow() from_date_utc = arrow_time_from.strftime("%Y-%m-%d %H:%M") to_date_utc = arrow_time_to.strftime("%Y-%m-%d %H:%M") from_date_str = arrow_time_from.to(timezone).strftime("%Y-%m-%d %H:%M") to_date_str = arrow_time_to.to(timezone).strftime("%Y-%m-%d %H:%M") range_hours = range_h_int else: #Convert datetimes to UTC so we can retrieve the appropriate records from the database from_date_utc = arrow.get(from_date_obj, timezone).to('Etc/UTC').strftime("%Y-%m-%d %H:%M") to_date_utc = arrow.get(to_date_obj, timezone).to('Etc/UTC').strftime("%Y-%m-%d %H:%M") difference = (arrow.get(to_date_obj, timezone) - arrow.get(from_date_obj, timezone)) range_hours = (difference.total_seconds()) / 3600 conn = sqlite3.connect('pi_temp.db') curs = conn.cursor() curs.execute("SELECT * FROM temperatures WHERE rDateTime BETWEEN ? AND ?", (from_date_utc.format('YYYY-MM-DD HH:mm'), to_date_utc.format('YYYY-MM-DD HH:mm'))) temperatures = curs.fetchall() curs.execute("SELECT * FROM humidities WHERE rDateTime BETWEEN ? AND ?", (from_date_utc.format('YYYY-MM-DD HH:mm'), to_date_utc.format('YYYY-MM-DD HH:mm'))) humidities = curs.fetchall() conn.close() return [temperatures, humidities, timezone, from_date_str, to_date_str, range_hours] def validate_date(d): try: datetime.datetime.strptime(d, '%Y-%m-%d %H:%M') return True except ValueError: return False if __name__ == "__main__": app.run(host='0.0.0.0', port=port)